/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import {Pipe, PipeTransform} from '@angular/core';
import {isObservable, of} from 'rxjs';
import {catchError, map, startWith} from 'rxjs/operators';
import {LoadingValue} from "@app/modules/shared/model/loading-value";

@Pipe({
  name: 'withLoading'
})
export class WithLoadingPipe implements PipeTransform {
  transform(val) {
    return isObservable(val)
        ? val.pipe(
            map((value: any) => {
                if(value instanceof LoadingValue) {
                    return value as LoadingValue<any>;
                } else {
                    return LoadingValue.finish(value);
                }
            }),
            startWith(LoadingValue.start()),
            catchError(error => of(LoadingValue.error(error)))
        )
        : val;
  }
}
